Labor für Virtuelles Studio / Virtuelle Realität

Automatic Camera and Switcher Control for Live Broadcast using Scene Analysis and Expert System (2015)

Live video broadcasting requires a multitude of professional expertises to enable real-time multi-camera productions. Unlike manually operated cameras, robotic systems allow the automation of common and repeated tracking shots. However, predefined camera shots do not allow quick adjustments when required due to unpredictable events. In this paper we introduce a modular automated camera control and video switch system, based on fundamental cinematographic rules and principles as they are used in feature ﬁlm and studio productions. By using the positional information of the actors provided by a markerless tracking system and the sound level of lavalier microphones, the current situation in the scene is analyzed by an expert system, which determines appropriate camera angles and decides when to switch from one camera to another. Based on this evaluation and the physical constraints of the robotic camera, low-level modules operate the robotic camera to establish the appropriate shot, and control the video switcher, which performs the required transitions. A test production was done to observe the developed prototype in a live broadcast scenario and served as a video-demonstration for an evaluation based on questionnaires and interviews with experts to show possible challenges and suggestions for further developments.

Application of a Moderator Tracking for Camera Control in a Virtual (TV) Studio (2014)

Markerless actor tracking for Virtual TV Studios enables sophisticated real-time robotic camera control. We demonstrate a semi-automatic prototype, which uses cinematographic rules in combination with the tracked positions of the actors to determine appropriate camera angles. The operator of a manually operated camera is able to switch the playout between automatic and manual camera by interacting with a mobile device. This trigger is also used to assign the determined parameters to the robotic camera. Two different shot types, the “over-the-shoulder” and “master” shot, were implemented. We discuss advantages and problems of such a system for standard formats by evaluating a test production.